For many years, circular hosiery knitting machines were driven by belts engaging pulleys spaced along a driven line shaft. Each of the knitting machines included a belt shifting mechanism for moving the flat drive belt between an idler pulley, a low speed pulley and a high speed pulley mounted on one outwardly projecting end portion of the main drive shaft. The main drive shaft also included other drive gears drivingly connected to drive pinions on the cylinder drive shaft. The cylinder drive shaft was provided with rotary and reciprocatory drive pinions and clutch collars which were selectively engaged by a clutch to either impart rotary or reciprocatory motion to the cylinder drive shaft. The large number of gears and drive pulleys involved in driving the machine and selectively imparting rotary or reciprocatory movement at different speeds to the needle cylinder increased the noise and vibration generated by the drive gears and also played an important role in limiting the operating speed of the needle cylinder.
In order to eliminate the speed change pulleys and belt shifting mechanism used in circular hosiery knitting machines, it has been proposed that the knitting machine be provided with a speed change device, interposed either between the line shaft and the machine or between an individual drive motor and the machine. For example, U.S. Pat. Nos. 2,736,178; 3,390,548; and 3,390,751 illustrate knitting machines provided with such speed change devices. However, the addition of the speed change device did not change the conventional rotary and reciprocatory gear drive mechanism of the knitting machine and the above-mentioned problems of noise generation, vibration and speed limiting factors were not eliminated. In all of the aforementioned conventional drive arrangements, a segment gear continuously reciprocates in back-and-forth unrestricted movement during both reciprocatory and rotary movements of the needle cylinder and tends to limit the top operating speed of the machine. This unrestricted back-and-forth movement of the segment gear also produces noise and vibration in the driving gears.